There has long been recognized the need for a simple device to aid in the transferring movement of a wheelchair assisted passenger in and out of the passenger compartment of an automobile.
In the case of small children or infants, the child's weight may be low enough to enable a parent or caregiver to simply lift the small child between a wheelchair and a conventional child car seat. This stage in a child's life is generally quite short and as the child grows the caregiver may be subject to back injury due to the lifting and turning movements required.
In the case of adolescents and adults, such passengers may be physically able to enter the passenger compartment with some assistance, or may require the use of specially designed vans with wheelchair elevators. The physical capabilities, weight and size of adolescents and adults generally dictates the choice between use of a specially designed vehicle, or use of a conventional passenger car with the wheelchair passenger substantially assisting in movement between the wheelchair and passenger compartment.
The invention is directed to the need for a transfer device for use with a conventional roofed passenger vehicle which will allow passengers to be transferred from a wheelchair to the passenger compartment without subjecting the passenger to physical handling, and which substantially eliminates risk of injury to the passenger and caregiver.
Prior art responses to this need have been partially successful. However, widespread adoption of such devices has proved to be elusive. In practical terms the choice remains between manual handling of passengers and purchase of a relatively expensive specially designed wheelchair transport van.
U.S. Pat. No. 2,650,725 to Hoyer et al provides a roof mounted lift for transferring a wheelchair passenger into a car passenger compartment. The passenger is fitted with two slings around the back and knees and is lifted with a manually operated hydraulic lift.
The disadvantages of the Hoyer system are the positioning of a rigid lifting hook immediately in front of the passenger's face, which poses a safety risk especially with children and those with limited muscular control, and the use of slings which increases the labour and handling involved. Hoyer's lifting device is stored on the roof rack exposing it to vandalism, damage, weather, corrosion, and detracts visually from the car appearance. Hoyer's device is also heavy and since it is manually positioned and operated, the device is relatively difficult for caregivers to use.
Furthermore, Hoyer's device does not adequately address the postural support needs of individuals requiring specialized seating during the transfer and while being transported in a motor vehicle.
U.S. Pat. No. 5,540,539 to Wolfman et al provides a transfer chair that is lifted with a hydraulic elevator arm bolted to the body and door of a passenger car. The requirement of modifying the vehicle to install a relatively large structural element such as the lift arm involves significant cost and labour. Clearly, such a permanently installed device is not practical for use with rental cars, or when temporary use of a vehicle is required.
Several prior art devices include a frame mounted to a car seat, with a removable insert seat to eliminate the need to manually handle children when transferred between carriages or wheelchairs and a passenger vehicle. For example, such prior art includes U.S. Pat. Nos. 5,265,931 to Ryan, one of the present inventors; 5,385,386 to Beamish et al; 4,874,203 to Henley et al; and 4,750,783 to Irby et al. However none of these prior art devices include integral means to lift the passenger, but rather manual lifting is contemplated.
It is desirable therefore to produce a simple relatively inexpensive mechanical transfer device that can be used in association with a conventional roofed passenger vehicle. Preferably, the device is easily installed and removed with minimal disruption to the vehicle structure and minimal labour.